package/vlc: install vlc libraries in staging

Although no package seems to link against vlc libraries right now, these
libraries will be necessary for upcoming new efl emotion-generic-players
package.

Signed-off-by: Romain Naour <romain.naour@openwide.fr>
Acked-by: Bernd Kuhls <bernd.kuhls@t-online.de>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>